A mechanical seal device is used for a chemical device, for example, a device using chemical liquid to cause corrosion of metal, or is used for shaft sealing of devices which treat process fluid for petroleum processing, for petrochemical, for pulp and paper, it is necessary to prevent reducing performance due corrosion of components of the mechanical seal device or adhering with the components. Also, a technology which is available to mount the mechanical seal easily, easily assembling, disassembling and inspection is required. Further, the mechanical seal device having reduced manufacturing cost is required. Further, when sealing sealed fluid such as oil and chemical liquid having large viscosity, a technology is required to prevent reducing sealing capability of seal face of a sealing ring due to solidification of the sealed fluid to a device. In recent years, a technology is required to simplify constitution of the mechanical seal device due to such technical background, for preventing functional depression of a sliding face as well as preventing corrosion of components.
Therefore, with respect to prior arts according to the present invention, there is a mechanical seal device which is shown in FIG. 3 (refer to Patent Document 1). FIG. 3 is a whole cross sectional view of a mechanical seal device 100 attached to a casing 160. This mechanical seal device 100 can be used as a shaft seal device for activating chemical liquid, etc.
Firstly, a constitution of this mechanical seal device 100 will be specified simply. In FIG. 3, the mechanical seal 100 seals a betweenness of the casing 160 and a rotary shaft 150 provided in a bore peripheral surface 160A (also referred as inboard “A”) of the casing 160. Also, the mechanical seal device 100 is made as a cartridge type which is mounted to a tip end face 160B of the casing 160, for easily mounting. In this mechanical seal device 100, a fixed seal ring 102 (also, referred as movable seal ring) provided in the bore peripheral surface 160A of the casing 160 and a rotary seal ring 112. Further, a case body 130 for maintaining the fixed seal ring 102 and a supporting body 106 to which the fixed seal ring 102 is equipped at outboard B of the casing 160, and a sleeve 125 for rotatably maintaining the rotary seal ring 112 at an inner side of the bore peripheral face 160A are main constitutional components of the mechanical seal device 100.
This rotary seal ring 112 is, in order to be provided in a space shown by a length L of the inboard “A” in the bore peripheral face 160A of the casing and a space D of a radial direction, fit with an inner circumferential face 125C of a long sleeve 125 to the rotary shaft 150 and is equipped with a connection component 126 which connects with one end portion of the inboard “A” side. Then, another end portion of the outboard side “B” side of the sleeve 125 is connected with a supporting portion 127 and fixing the sleeve 125 and the rotary shaft 150 by threading a screw socket 128 to a screw portion provided on the supporting portion 127. each of fitting spaces between the sleeve 125 fit with the rotary shaft 150 and a connection component 126 fit with the sleeve 125 are sealed by O-rings for sealing arranged on mounting grooves provided on the sleeve 125. Also, the sleeve 125 and the connection component 126 are connected via a drive pin 129. Further, the connection component 126 and the rotary seal ring 112 are connected by locking with a drive pin and a groove having U-shape (also referred as notch) of an axial direction without numerical references within respective mating. Further, this mating space is sealed by an O-ring 141 provided between the connection component 126 and the rotary seal ring 122.
On the other hand, the fixed seal ring 102 is maintained by fitting with a stepped face 106D at an inner circumferential face 106C provided at one end portion of the supporting body 106 which is a cylindrical shape. Also, the supporting body 106 is unrotatably supported with the case body 130 by fitting of a fixing pin 137 which is provided on the case body 130 and a groove 106G, and movably fits toward the axial direction. A fitting space between the supporting body 106 and the case body 130 is sealed by an O-ring 143 arranged between a first stepped face 106A of the supporting body 106 and a second stepped face 130A of the case body 130. Then, a ring shape spring receiving section is fitted to a groove of another end portion of the supporting body 106.
The case body 130 joints an end portion 130F to a tip end face 160B of the casing 160, and fixes to the casing 160 with fastening a nut 128A to a stud bolt which is coupled with the casing 160. A stepped face is provided at an inner circumferential side of a side face of the case body 130. A spring seat 107 is attached to the stepped face by a lock screw section. Also, a spring 120 supported at the spring seat 107 is provided between a spring receiving section to bias the fixed seal shaft 102 elastically by a spring 120 with the spring receiving section and the supporting body 106. A sealing face 102 of the fixed seal ring 102 biased by the spring 120 seals sealed fluid which exits at an outer circumferential side by hermetically contact with a counter seal face 112F of the rotary seal ring 112. Also, a mounting groove having ring shape is provided at an inner circumference of the spring seat 107. A spirally wounded gasket 146 is provided at the mounting groove. A seal face of the gasket 146 closely contacts with an outer circumferential face of the sleeve 126 so as to seal leakage of a quenching fluid to the outboard B.
Also, for cooling a sliding of the rotary seal ring 112 and the fixed seal ring 102, a flushing path 136 is provided at the case body 130 which communicates through an outer circumferential face 126B of the connection component 126 to which the rotary seal ring 112 is equipped and a flashing passage of an outside of an outer circumferential face 1068 of the supporting body 106 to which the fixed seal ring 102 is equipped. A quenching passage 135 which communicates with an inner circumferential face 106 of the supporting body 106, an inner circumferential face of the fixed seal ring 102 and a cooling passage S at an inside of an inner circumferential face of the rotary seal ring 112. Then a flushing fluid which flow outs from the flushing passage 136 flows into the cooling passage S to cool the rotary seal ring 112 and the fixed seal ring 102.
In the mechanical seal device 100 constituted in this manner, because it is necessary to provide the fixed seal ring 102 and the rotary seal ring 112 at a position which contact with process fluid such as chemical, etc., at the inboard “A” side of the bore peripheral surface 160A in the casing 160, the supporting body 106, the connection component 126 and the sleeve 125 which are metal corrode by the process fluid. Also, it is necessary to wash an outer peripheral side of the rotary seal ring 112 and the fixed seal ring 102 by providing a flushing passage 136 at the case body 130. This flushing fluid shall be the same with the process fluid, it will fear of adverse effect because it will be mixed into the process fluid. Therefore, it is necessary to pressure sending a part of the process fluid to the flushing passage 136 by a pump, even in case of mixing into the process fluid. However, the pump and the case body 130 are corroded by the process fluid. Further, because it is necessary to provide the rotary seal ring 112 at the “A” side of the bore peripheral face 160A of the casing, the sleeve 125 to fix the rotary seal ring 112 will be necessary as well as it will be complicated structure because the connection component 126 have to be equipped.
Also, it is necessary to cool the rotary seal ring 112 and the fixed seal ring 102 by providing the quenching fluid at an inner circumferential side of the rotary seal ring 112 and the fixed seal ring 102. However, because the quenching fluid flows into an inner circumferential side of a seal face 102F of the fixed seal ring 102 and a counter seal face 112F of the rotary seal ring 112, there will be a risk of problem that the quenching fluid is mixed with different kinds of process fluid due to the quenching fluid such as pure water, etc. leaks outside by sliding movement as well as a centrifugal force when the seal face 102 and the counter seal face 112F slide relatively.
Further, as mentioned above, it is necessary to provide the supporting member 106 to the fixed seal ring 102. Simultaneously, it is necessary to provide the connection component 126 at the rotary seal ring 112. Therefore, the sleeve 126 becomes long length as a length “L” towards to the inboard “A” depth of the bore peripheral face 160A at the casing 160. As a result, because the flushing fluid flows through a narrow flushing passage at an outer circumferential face side of the rotary seal ring 112 and the fixed seal ring 102, the cleaning effect for flushing the rotary seal ring 112 and the fixed seal ring 102 is reduced. Also, similarly, an inner circumferential side of the rotary seal ring 102 and the fixed seal ring 112 is formed as a narrow cooling passage “S” and the quenching fluid flows through, a flow amount of the quenching fluid becomes small, thus a cooling effect for cooling the fixed seal ring 102 and the rotary seal ring 112 is reduced. Further, in case of a sealed fluid having high viscosity, due to adhering with a betweenness of the seal face 102F and the counter seal face 112F and a betweenness of the O-ring 143, the first stepped face 106A and the second stepped face 130A, there will be a risk of problem to reduce sealing capability of each of the seal faces 102F, 112F and the O-ring.
Patent Document 1: Japanese Patent Laid Open No. 11-13894
Patent Document 2: Japanese Utility Model Laid Open No. 2-94973